Field of the Invention
The present invention relates to a process cartridge capable of being detachably attached to an apparatus body of an image forming apparatus.
Description of the Related Art
An image forming apparatus which uses an electrophotographic technique generally requires maintenance of various process means, replenishment of toner, and other operations. A process cartridge is known in which a process means such as a photosensitive drum, a charging means, a developing means, and a cleaning means are integrated as a cartridge in order to perform replenishment of toner, maintenance, and other operations easily. The process cartridge is capable of being detachably attached to an apparatus body of an image forming apparatus. A user can easily perform maintenance of process means, replenishment of toner, and other operations by replacing the process cartridge.
Moreover, a process cartridge is proposed in which a handle for allowing a user to easily replace and carry the process cartridge is formed on a frame of the process cartridge (see Japanese Patent Application Publication No. 2002-328586). This handle is pivotably relative to the process cartridge body. The pivotal axis line of the handle is positioned so as to overlap the center of gravity of the process cartridge body when seen from a vertical direction in an attitude (hereinafter referred to as an attached attitude) when the process cartridge is attached to an image forming apparatus body in a state in which the image forming apparatus is installed on a horizontal surface.
Here, the process cartridge body is a portion of the process cartridge excluding the handle. Since the pivotal axis line of the handle is positioned in this manner, it is possible to maintain the attitude of the process cartridge in the attached attitude when a user grasps the handle to carry the process cartridge.
However, since the amount of toner in the process cartridge decreases with the use of the process cartridge, the position of the center of gravity of the process cartridge body may move before and after the use of the same process cartridge. Here, FIGS. 10A and 10B are diagrams illustrating the state of a process cartridge when a handle provided in a conventional process cartridge is grasped. FIG. 10A is a diagram illustrating the state of the process cartridge before use. Moreover, FIG. 10B is a diagram illustrating the state of the process cartridge after use.
As illustrated in FIGS. 10A and 10B, the center of gravity of the process cartridge body may be shifted by distance Z before and after the use of the process cartridge. In the technique disclosed in Japanese Patent Application Publication No. 2002-328586, the pivotal axis line of the handle is positioned so as to overlap the center of gravity of the process cartridge body when seen from the vertical direction in an attached attitude of the process cartridge. Thus, in the technique disclosed in Japanese Patent Application Publication No. 2002-328586, when a user grasps the handle of the process cartridge after use, the process cartridge is greatly inclined relative to the attached attitude.